In recent years, as a multimedia environment is established, various terminals and networks have been used and accordingly requirements of a user have been diversified.
For example, as the performance and computing capability of a terminal are diversified, the supported performance has been also diversified for each device. Further, a network such as a wired/wireless network through which information is transmitted has various functions such as an outer appearance structure, a form of transmitted information, and information amount and rate. The user selects a terminal and a network to be used according to a desired function. In addition, spectrums of the terminal and the network provided to the user from an enterprise have been diversified.
Accordingly, recently, broadcasting having a High Definition (HD) resolution has been domestically and internationally extended and served so that many users are accustomed to seeing an image with a high resolution and high quality. Thus, a plurality of image service relation centers has greatly attempted to develop a next generation image device.
In addition, as there is growing interest in HDTV and Ultra High Definition (UHD) with resolution of four times or greater than the HDTV, there is a great need for a technology to compress and process a high quality image with high resolution.
In order to compress and process the image, an inter prediction technology of predicting a pixel value included in a picture between previous and/or next pictures and a current picture, an intra prediction technology of predicting other pixel value included in the current picture using pixel information in the current picture, and an entropy encoding technology of allocating a short code to a symbol with high appearance frequency and allocating a long code to a symbol with low appearance frequency may be used.
As described above, when considering respective terminals and networks having different supported functions and various requirements of the user, there is a demand to change the quality, the size, and a frame of the supported image.
In this way, due to heterogeneous communication networks and various functions and types of terminals, scalability variously supporting the quality, the resolution, the size, and a frame rate, a view of the image becomes an important function of a video format.
Accordingly, in order to provide a service required by a user in various environments based on a high-efficiency video encoding method, there is a need to provide a scalability function so that efficient video encoding and decoding may be performed in time, space, image quality, and view sides.